Breast cancer is one of the most common cancers and is often identified as being the second cause of cancer death in women. In 2001, the incidence rates of breast cancer were 90-100/100,000 in the United States and 50-70/100,000 in Europe. The incidence of the disease is growing worldwide. Risk factors for breast cancer include race, age, and mutations in the tumor suppressor genes BRCA-1 and -2 and p53. Alcohol consumption, fat-rich diet, lack of exercise, exogenous post-menopausal hormones and ionizing radiation also increase the risk of developing breast cancer. Estrogen receptor and progesterone receptor negative breast cancer (“ER-” and “PR-” breast cancer, respectively), large tumor size, high grade cytology and age below 35 years are associated with a bad prognosis (Goldhirsch et al. (2001). J. Clin. Oncol. 19: 3817-27). In 2005 an estimated 212,000 new cases of invasive and 58,000 new cases of non-invasive breast cancer will be diagnosed, with 40,000 women expected to die from breast cancer.
New strategies are needed for treatment of cancers.